Congenital cardiovascular anomalies induced by pteroylglutamic acid deficiency during gestation in the rat.

Congenital cardiovascular anomalies were observed in the offspring when rats were placed on a dietary regimen deficient in pteroylglutamic ("folic") acid during gestation. These cardiovascular malformations occurred only when the mothers were given this diet for specific periods, as short as two or three days, in early pregnancy, at a time when the heart and aortic: arches were in the initial stages of development.